Process for treating animal tissues and products obtained therefrom



-5 the well known'way Patented Sept, 13, 1 927.

UNITED STATES} PATENT oFFIcE.

rnmnnrcn w. wanna, or" nAcxnN/sacx, new mnsny.

Io Drawing. Application fled am 19, 1925, Serial no; 16,861.Renewedlanuary 31, 11127.-

This invention relates to certain products obtained from animal tissue,for instance from animal hides after they have been dehaired andotherwise prepared by any of s the object of the in.- .vention beingtoproduce a leather of supe- ,riorwhiteness and of unusual lastingproperties compared with that prepared by the processes of the priorart; it is also an ob- 10 ject of, the invention to produce suchsuperior leather also at a low price and with other economicaladvantages.

The subject-matter of th1s application is a continuation in part of theorigmal co .15 pending application, entitled .Method of treating animaltissue and products obtained therefrom, Serial No. 704,282, filed April4, 1924. I

In the present art of, tanning the 'utiliza-.

2. tion of alum plays a great; part though itsapplication entailsconsiderable econom' ical as well 'as technical disadvantages. One ofthecauses of these short comings is its high content of water whichcauses use- 5 less expense for freight and as the alum 1 must bedeprived. of its iron'content-before use.

it is applied to the tanning process the originally low priced materialhas already be come rather expensive when it 1s ready for It is alsopossible that leather produced by a tanning process-using alum as atanning agent will retain' sulfuric acid within its intercellular spacesso that it is absorbed by the tissue and in the course of time will acton the leather'and' will render it brittle; such leather will theneasily crumble to pieces on being handled. v

I j Notwi hstanding" such considerable shortdescribed in my originalapplication re-f for tanning urposes because it has been found verydlfiicult to find a tute for the same. I have ound out, as

'ferred to above, that the compounds of the rare earth metals readilyact .as tannin agents as far as the quality of the leather an the costof its reduction is concerned. I have also foun that the cost ofmaterial for the production of a superior leather accordin to my processis not higher than that o the processes of the prior art and that it isactually lower in view of the great advantages owing to the saving oftime and. .labor allowed-by the great slmplicity and.

unfailing results of my. new process.

comings alum is .applied on a large scale proper substi-.

For the better understanding of my na'ge with alum a certain amount ofsodium .chloride is added; practical tanners maintain that on account ofits 'hygroscopity the ventionI-refer to "the factthat in the tansodiumchloride in the animal tissue later on softens the same after it haspassed the tanning rocess. On theother side it is claimed t at theaddition of sodium chlor1de to the tanning liquor containing alu-i minumsulfate causes a double decomposition of- Al l +Na SO of which A101 issupposed to act as the real tanning agent. The contentions of both bythe experiments of napp, (Die Natur und das Wesen der Gerberei-Chemie,1858; Ueber Gerb'erei 11nd Leder, Di'nglersches Polytechni- Journal,vol." 181, pg. 311;

Rogers, Practical Tanning, 1922, Carey,

Baird &' 00., New York; 'Brit. Pat. 2716- tion to .take lace whichresults in the formaartiesare refuted 1361; D; R. P.v 444 and 10.518),said experi-' merits proving that a solution ofAlC'l -does not actdifferently upon albumen from a solution of aluminumsulfate and that in.both cases the desired coagulate can only be obtained upon the.addition of sodium chloride. P

' While ,I have described inmy original application referred to abovethat I' can. produce a leathersuperior inwhiteness and softness to thebest French kid leatherif I applyone-or a plurality of acetates ofitherare earth metals, without exception, I have now found.- out that thesituation is not governed by the samegeneralization if the chlorides ofthe rare earth metals are considered; I have found that I can' produce aleather of excellent whiteness by' treating, the hides, prepared in'theusual way, with a solution of the chlorides of all, or part,

free of cerium. 'By extensive emperi-ments I found that the absence ofcerous com-.

pounds, such 'as cerium chloride,- is necessary to obtain perfectlysatisfactory results as to whiteness and lasting properties. There 's nodoubt'thatcerous compounds cause t e hide to turn yellow and that thecontinuous alternate oxidation 0 the cerous oxide to ceri-oxide and thereduction of the latter to cerous oxide. These defects are neverobserved if one treats the pickled be considered practically identicalwith the oxides, or hydroxides, of the rare earth I been added toaforesaid solution.

' ning liquor.

metals in that these compounds are inert to leather. Some of theseelements occur in such small quantities that the solution consists moreof lanthan and didymchloride than of other chlorides if it is made fromthe residues obtained from the manufacture of chemicals for theincandescent gas light mantle from monazit sand. Such solutions,however, mixed with sodiumchloride, may be immediately applied. fortanning wit very satisfactory results for they display a very high powerof penetration and tanning effect.

I prefer, however, to proceed asfollows: The fresh hide, prepared in anyof thewell known ways, is first treated at approximately 37 deg. C. witha 5% neutralisodium or potassium soap solution. The hide, thussurcharged with soap, is then set up to drain off, or to otherwiseremove in any suitable way the mechanically adhering soap, and

then it. is immersed into the tanning liquor consisting of a solutionof, a mixture of all, or part, or any of the chlorides, or basicchlorides of the rare earth metals with the exception of cerium, sodiumchloride having Accordin to the nature of the-acid, or acids, containedin the soap, for instance oleic, stearic' or palmitic acid etc., therespective salt of the rare earth metals is immediately formed uponthe'immersion of-the hide in the tan- I I wish to state in this regardthat the hide should not be impregnated first with the tanning liquor tobe subseuently immersed into the soap solution, as t e metal saltsolution will then run out of the hide to from with the soap a foam onthe outside of the hide.

'In the process described in the preceding examples I may substitute allthe sodium chloride by sodium sulfate and furthermore art of the sodiumchloride by zinc sulfate.

I'he hide impregnated with such a tanning liquor containing zinc sulfateis then subsequently acted uponv with di-sodiumphosphate whereby thephosphates :of the rare earth metals and that of zinc are precipitatedwithin the hide in the form of compounds inert to leather whereby aproduct of excellent whitenessis obtained.

In this case I can also'proceed as follows: The hides, impregnated withthe tanning liquor of the chlorides, or basic chlorides,

emmas of aforesaid rare earth metals, free of cerium, but with anaddition of zinc sulfate and sodiumchloride, are worked at preferably 37deg. C. in a drum, or in or by any other suitable mechanical device,wlth a -mixture of egg yolk, flour, sodiumchloride and sodium phosphate,whereby I avoid from the first any loss by the running out of thetanning liquor and secondly I accomplish the double decompositionforming the phosphates of the rare earth metals and zinc underconditions which favor the formation of a jelly from the flour whichcontributes to yielding a better leather. As all elements combine in theproportion of their atomic weight the quantity of acid radicle inthemolecule of therare earth metal compounds is proportionately smallerthan in .the compounds of metals of low atomic weight, the amount ofacid to produce the neutral salt, or the amount of alkali to turn such asalt into a basic salt, regardless of whether the salt be a sulfate,chloride or acetate. the cost of the materials to these changesissmaller than with t e other chemicals applied up to now as tanningagents. Moreover, as the compounds coming in consideration for my newtanning process are, produced preferably from the residue obtained inthe manufacture of the salts for the impregnation of mantles forincandescent gas light, the facts in combirform Y nation with thefavorable circumstances pointed out above makes it self evident that mynew tanning process can successfully compete as to economy as well asquality of'products with any of the old tanning processes. (I

Finally I wish to point out that also the leathers produced by thisprocess bymeans of the chlorides of the rare earth metals are sterileand do not favor the growth of certain micro-organism so destructive toleather. This is im ortant because the sterilization of the hidesprevents their destruction'by the putrefaction caused by the i organicmatter, like flesh particles,,blood,j etc, adhering to the hides; on theother side it is very important that this sterilization be effected withmaterials which are not detrimental to the hides nor to the people whoare using the manufactures made from the sterilized leather. Forinstance formalis strikingly shown by the following te s'twhich'conslsted in moistenin leather, hav ing been tanned by any oft eabove processes, with ,water and subsequently. drying itin an open panat a temperature slightly above that of the atmosphere, andjzontinuingthese operations alternately for 22 weeks without generating eventheslightest 'esses, described above, is'es'pecially; suitable for leathergoods intended to be used in tropic climates where the heat and the'enormous amount of moisture in'theair combine to thoroughly covergoods,:m'adefrom leather tanned by the processes of the prior .1 a fewdays with a layer of mildew.

at I cla'im is:

' '1. The process of treatmghides,compris 1 ing acting .upon the hides,in the presence of sodium chloride with the solution of a rare earthmetal other than'ceriuin. '2. The process of treating hides, comprisingacting ii on the hides, in the presence of'sodium .c loridewith aplurality of chlorides of the rare earth metals otherthan cerium.

3. The processfof treating animal tissue, comprising acting upon thetissue, prepared in any'of the well knowm'ways, first with a solution ofa salt, capable of precipitating an insoluble salt from a solution ofa-chloride of'a rare earth metal, and subsequentl 'acting upon thetissue,-thusimpreg nate "with the solution of a chloride of a rare"earth metal, other than 'ceriumfin" the pres- .-ence of sodiumchloride.

' 4. The process of treating hides, compris- .ing acting upon the hides,first with a solution of a soap andsubsequently acting upon thehides,thus-impregnated, inthe presence of sodium chloride with a solution ofa. chloing acting upon the hide's,.- in the v subsequentl impr ate in te presence of sodium -chlor' c with the solution-of a chloride of arare'earth metal other than cerium.

. ride ofa rare earth metal other thancerium.

' 5. The process of treating-hides, comprising acting at approximately.37 de'gx'G. upon the. hides, first with a solution of soap and actinupon the hides, thus 6. The process of treating hides, comprisof, i umch oride an zinc sulfate with the so ution of a chlorideiof a rareearthmetal' other than cerium and subsequently acting pon -the hide thustreated with a solution of sodium phosphate.

ing acting uponthe "hides, infthe presence 'ofsodium chloride and zincsulfate with the. solution .of 'a' plurality "of chlorides of rare earthmetals, other than cerium, and subsequently acting-upon .the hides thustreated with a solution of sodium phosphate.

trace of mildew. It. is obvious therefore that leather, obtained. by anyof theprocing acting upon the hides, first with a solu; tion-of soap andsubsequently acting upon hides in the. presence of sodium chloride-andzinc sulfate with a chloride of a rare earth metal other than cerium andthen 8. Theprocess of treating hides, compris- 7. The process oftreating-hides, compris-v a acting upon the hide thus treated with-asohides, compris-l of chlorides of rare earthmetalsother than cerium andtherf acting'upon the hides with a solution 'of sodium phosphate.

10. The process of sterilizinghides, comprising actingupon' the,rawhides, from whichthe flesh particles and other organic matter hasbeen removed, with asol'ution of soap and subsequently'acting'upon thehidej" 1n the. presence of sodium-fchlo ude and-zinc sulfate with achloride of a rare earth metal botherthan ceriumand subsequently g thehides thus-treated with a soluti n aphosphate.

leather containing in its fibers a de' osit of .comp'ounds'formed by thehide-su stance with the aqueous solution of a chlorideofa. rare earthmetal other than'ce-rium; I

compounds formed. by the hide-substance --,th an cerium, in the presenceof soap. s

' 'Invtestimony whereof hereuntoaflix mysignature. j. v .1 r WEBER.

witha chloride of 'a rare earth metal, other 11.As a new article ofmanufacturm 'a" 12.As a new article of manufacture, aff leather havingin its fibers afdeposit of j f

